1. Field of the Invention
The present invention relates to the production of slide fasteners, and more particularly to a slide fastener having a pair of intermeshable top end stops.
2. Description of Prior Art
In the manufacture of slide fasteners, it has been a known practice to thread individual sliders one after another onto a continuous slide fastener chain to which a plurality of pairs of top end stops and a plurality of bottom end stops (or separable bottom stop assemblies) have been attached beforehand. To this end, various types of top stop assemblies have been proposed which allow a slider to be moved past the top end stops during the threading and which then prevent the slider from being moved past the same top end stops after the threading.
One example of such top stop assemblies, as disclosed in Japanese Utility Model Post-Examination Publication (Jikkosho) No. 46-6577 and reillustrated in FIG. 7 of the accompanying drawings, comprises a pair of top end stops 1, 2 each having a guide recess 3, 4 extending from its upper end and terminating short of its lower end. Both the width and the depth of the recess 3, 4 decrease gradually from the upper end to the lower end of the individual top end stop 1, 2. This recess 3, 4 thus serves as a one-way path for one of opposite side flanges 5, 6 of a slider 7; the two top end stops 1, 2 resiliently deform when the side flanges 5, 6 of the slider 7 are forced past these top end stops 1, 2 during the threading. The major problem with this prior art construction, however, is that the top end stops 1, 2 as well as the slider 7 are apt to be unrecoverably deformed or damaged. Further, since the top end stops 1, 2 cannot enter the slider 7 when the latter is pulled to close the slide fastener all the way after the slider 7 has been threaded onto a pair of fastener element rows, this known slide fastener was found to be not neat in appearance.